00:01
We're asked to find the inverses derivative at the c value of root 3.
00:11
But before we kind of venture down that road, we need to figure out that f of x is 1 to 1 on that interval of negative pi over 2 to positive pi over 2, which is very important.
00:31
And you can even look at the graph of tangent and how if you go beyond pi over 2, it's starts repeating itself.
00:40
And so by not having this restriction on here, it would not be one to one.
00:45
But that's not actually showing the work.
00:47
What they want you to do to show that work is to know that the derivative of tangent is sequenced, which is always positive, whether you get negative values for secant.
00:58
Once you square it, you'll get a positive.
01:00
But again, we need this restriction on this interval.
01:06
Because if the derivative is positive then f is increasing and if it's strictly increasing then yes we are one to one so what happens by restricting is we get to erase this value now to me the next toughest part is figuring out where the because this is the x value of the inverse so it's got to be the y value of the original function so what you have to think about is and i'm going to draw all the unit circle so tangents positive in this quadrant, the first quadrant, and it's either this ordered pair, whoops, i put that the wrong spot, it is the right ordered pair...